Topics
Units and Measurements
Mathematical Methods
Motion in a Plane
Laws of Motion
- Introduction to Laws of Motion
- Aristotle’s Fallacy
- Newton’s Laws of Motion
- Inertial and Non-inertial Frames of Reference
- Types of Forces
- Work Energy Theorem
- Principle of Conservation of Linear Momentum
- Collisions
- Impulse of a Force
- Rotational Analogue of a Force - Moment of a Force Or Torque
- Couple and Its Torque
- Mechanical Equilibrium
- Centre of Mass
- Centre of Gravity
Gravitation
- Introduction to Gravitation
- Kepler’s Laws
- Newton’s Universal Law of Gravitation
- Measurement of the Gravitational Constant (G)
- Acceleration Due to Gravity (Earth’s Gravitational Acceleration)
- Variation in the Acceleration Due to Gravity with Altitude, Depth, Latitude and Shape
- Gravitational Potential and Potential Energy
- Earth Satellites
Mechanical Properties of Solids
Thermal Properties of Matter
Sound
Optics
Electrostatics
Electric Current Through Conductors
Magnetism
Electromagnetic Waves and Communication System
Semiconductors
description
- Range of Masses
notes
Measurement of Mass
Mass is a basic property of matter. It does not depend on the temperature, pressure or location of the object in space. The SI unit of mass is kilogram (kg).
While dealing with atoms and molecules, the kilogram is an inconvenient unit. In this case, there is an important standard unit of mass, called the unified atomic mass unit (u), which has been established for expressing the mass of atoms as 1 unified atomic mass unit
i.e. 1u = (1/12) of the mass of an atom of carbon-12 \[\ce{^12_6C}\] isotope including the mass of electrons
= 1.66 × 10–27 kg
Apart from using balances for normal weights, mass of planets is measured using gravitational methods and mass of atomic particles are measured using mass spectrograph (radius of trajectory is proportional to mass of charged particle moving in uniform electric and magnetic field).
Range of Masses
The masses of the objects, we come across in the universe, vary over a very wide range. These may vary from tiny mass of the order of 10-30 kg of an electron to the huge mass of about 1055 kg of the known universe. Table below gives the range and order of the typical masses of various objects.
Object | Mass (kg) |
Electron | 10-30 |
Proton | 10-27 |
Uranium atom | 10-25 |
Red blood cell | 10-13 |
Dust particle | 10-9 |
Rain drop | 10-6 |
Mosquito | 10-5 |
Grape | 10-3 |
Human | 102 |
Automobile | 103 |
Boeing 747 aircraft | 108 |
Moon | 1023 |
Earth | 1025 |
Sun | 1030 |
Milky way galaxy | 1041 |
Observable Universe | 1055 |